src/math/interaction.c

   1 /* PSPP - a program for statistical analysis.
   2    Copyright (C) 2011, 2012 Free Software Foundation, Inc.
   3
   4    This program is free software: you can redistribute it and/or modify
   5    it under the terms of the GNU General Public License as published by
   6    the Free Software Foundation, either version 3 of the License, or
   7    (at your option) any later version.
   8
   9    This program is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12    GNU General Public License for more details.
  13
  14    You should have received a copy of the GNU General Public License
  15    along with this program.  If not, see <http://www.gnu.org/licenses/>. */
  16
  17 #include <config.h>
  18
  19 #include "data/case.h"
  20 #include "interaction.h"
  21
  22 #include "data/value.h"
  23 #include "data/variable.h"
  24 #include "libpspp/str.h"
  25
  26 #include "gl/xalloc.h"
  27
  28 #include <stdio.h>
  29
  30 /* Creates and returns an interaction.  If V is nonnull, then the interaction
  31    initially contains V, otherwise it is initially empty. */
  32 struct interaction *
  33 interaction_create (const struct variable *v)
  34 {
  35   struct interaction *iact = xmalloc (sizeof *iact);
  36   iact->vars = xmalloc (sizeof *iact->vars);
  37   iact->n_vars = 0;
  38   if (v)
  39     {
  40       iact->vars[0] = v;
  41       iact->n_vars = 1;
  42     }
  43   return iact;
  44 }
  45
  46 /* Returns a (deep) copy of interaction SRC. */
  47 struct interaction *
  48 interaction_clone (const struct interaction *src)
  49 {
  50   struct interaction *dst = xmalloc (sizeof *dst);
  51   dst->vars = xmemdup (src->vars, src->n_vars * sizeof *src->vars);
  52   dst->n_vars = src->n_vars;
  53   return dst;
  54 }
  55
  56 /* Frees IACT. */
  57 void
  58 interaction_destroy (struct interaction *iact)
  59 {
  60   if (iact)
  61     {
  62       free (iact->vars);
  63       free (iact);
  64     }
  65 }
  66
  67 /* Appends variable V to IACT.
  68
  69    V must not already be in IACT. */
  70 void
  71 interaction_add_variable (struct interaction *iact, const struct variable *v)
  72 {
  73   iact->vars = xrealloc (iact->vars, (iact->n_vars + 1) * sizeof *iact->vars);
  74   iact->vars[iact->n_vars++] = v;
  75 }
  76
  77 /* Returns true iff the variables in X->VARS are a proper subset of the
  78    variables in Y->VARS. */
  79 bool
  80 interaction_is_proper_subset (const struct interaction *x,
  81                               const struct interaction *y)
  82 {
  83   return x->n_vars >= y->n_vars && interaction_is_subset (x, y);
  84 }
  85
  86 static bool
  87 interaction_contains (const struct interaction *iact, const struct variable *v)
  88 {
  89   for (size_t i = 0; i < iact->n_vars; i++)
  90     if (iact->vars[i] == v)
  91       return true;
  92   return false;
  93 }
  94
  95 /* Returns true iff the variables in X->VARS are a subset (proper or otherwise)
  96    of the variables in Y->VARS. */
  97 bool
  98 interaction_is_subset (const struct interaction *x,
  99                        const struct interaction *y)
 100 {
 101   if (x->n_vars > y->n_vars)
 102     return false;
 103
 104   for (size_t i = 0; i < x->n_vars; i++)
 105     if (!interaction_contains (y, x->vars[i]))
 106       return false;
 107
 108   return true;
 109 }
 110
 111 /* Prints the variables in IACT on stdout, for debugging purposes. */
 112 void
 113 interaction_dump (const struct interaction *iact)
 114 {
 115   if (iact->n_vars == 0)
 116     printf ("(empty)\n");
 117   else
 118     {
 119       for (size_t v = 0; v < iact->n_vars; ++v)
 120         {
 121           printf ("%s", var_get_name (iact->vars[v]));
 122           if (v + 1 < iact->n_vars)
 123             printf (" * ");
 124         }
 125       printf ("\n");
 126     }
 127 }
 128
 129 /* Appends STR with a representation of the interaction, suitable for user
 130    display.
 131
 132    STR must have been initialised prior to calling this function. */
 133 void
 134 interaction_to_string (const struct interaction *iact, struct string *str)
 135 {
 136   for (size_t v = 0; v < iact->n_vars; ++v)
 137     {
 138       ds_put_cstr (str, var_to_string (iact->vars[v]));
 139       if (v + 1 < iact->n_vars)
 140         ds_put_cstr (str, " × ");
 141     }
 142 }
 143
 144 /* Returns a hash of the values in C given by variables in IACT, using BASE as
 145    a basis for the hash. */
 146 unsigned int
 147 interaction_case_hash (const struct interaction *iact,
 148                        const struct ccase *c, unsigned int base)
 149 {
 150   size_t hash = base;
 151   for (size_t i = 0; i < iact->n_vars; ++i)
 152     {
 153       const struct variable *var = iact->vars[i];
 154       const union value *val = case_data (c, var);
 155       hash = value_hash (val, var_get_width (var), hash);
 156     }
 157   return hash;
 158 }
 159
 160 /* Returns true iff all the variables in IACT have equal values in C1 and
 161    C2. */
 162 bool
 163 interaction_case_equal (const struct interaction *iact,
 164                         const struct ccase *c1, const struct ccase *c2)
 165 {
 166   for (size_t i = 0; i < iact->n_vars; ++i)
 167     {
 168       const struct variable *var = iact->vars[i];
 169       if (!value_equal (case_data (c1, var), case_data (c2, var),
 170                         var_get_width (var)))
 171         return false;
 172     }
 173
 174   return true;
 175 }
 176
 177 /* Returns a strcmp()-like comparison result for the variables in IACT and
 178    their values in C1 and C2. */
 179 int
 180 interaction_case_cmp_3way (const struct interaction *iact,
 181                            const struct ccase *c1, const struct ccase *c2)
 182 {
 183   for (size_t i = 0; i < iact->n_vars; ++i)
 184     {
 185       const struct variable *var = iact->vars[i];
 186       int cmp = value_compare_3way (case_data (c1, var), case_data (c2, var),
 187                                     var_get_width (var));
 188       if (cmp)
 189         return cmp;
 190     }
 191
 192   return 0;
 193 }
 194
 195 /* Returns true iff any of the variables in IACT have a missing value in C,
 196    using EXCLUDE to decide which kinds of missing values to count. */
 197 bool
 198 interaction_case_is_missing (const struct interaction *iact,
 199                              const struct ccase *c, enum mv_class exclude)
 200 {
 201   for (size_t i = 0; i < iact->n_vars; ++i)
 202     if (var_is_value_missing (iact->vars[i], case_data (c, iact->vars[i]))
 203         & exclude)
 204       return true;
 205
 206   return false;
 207 }
 208